I have a Miller Maxstar 200 SD, used primarily as a stick welder in a boiler service company. It has random P-8 fault codes and when it does work, the welding out put shuts off everytime the cooling fan cycles, whether your welding or not, but it can also shut off after every stick run. Then it may run fine for 1-2 days, then back to its antics. It has been looked at by the local authorized service center 4 times, they say, each time they said one of the ribbon cables was loose (other than that they say they can find nothing wrong). I'd get it back and within hours its back to the same old issues. They have it again for the fifth time, I'm extremely frustrated.

As the unit is used in a mobile repair business it see different voltages on a daily basis, issues are the same regardless of voltage input. The vast majority of the welding is done in the 75-125 amp output range, using 6010, 6011 and 7018 rod. The welder rides in a padded secure wood box in the truck, its kept clean and dry and when working properly a joy to work with, but the issues continue.